CryptoPkg/OpensslLib: Add AArch64Cap for arch specific hooks

Add AARCH64 specific implementations of:
- OPENSSL_cpuid_setup(), probing hardware capabilitie
  (presence of FEAT_AES, etc.)
- OPENSSL_rdtsc(), returning non-trusted entropy by accessing
  system counter.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>

CryptoPkg/Library/OpensslLib/OpensslLibAccel.inf

@@ -1329,6 +1329,7 @@
 # Autogenerated files list ends here
 
 [Sources.AARCH64]
+  OpensslStub/AArch64Cap.c
 # Autogenerated files list starts here
   $(OPENSSL_PATH)/crypto/aes/aes_cbc.c
   $(OPENSSL_PATH)/crypto/aes/aes_cfb.c

CryptoPkg/Library/OpensslLib/OpensslLibFullAccel.inf

@@ -1432,6 +1432,7 @@
 # Autogenerated files list ends here
 
 [Sources.AARCH64]
+  OpensslStub/AArch64Cap.c
 # Autogenerated files list starts here
   $(OPENSSL_PATH)/crypto/aes/aes_cbc.c
   $(OPENSSL_PATH)/crypto/aes/aes_cfb.c

CryptoPkg/Library/OpensslLib/OpensslStub/AArch64Cap.c

@@ -0,0 +1,107 @@
+/** @file
+  Arm capabilities probing.
+
+  Copyright (c) 2023 - 2024, Arm Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <openssl/types.h>
+#include "crypto/arm_arch.h"
+
+#include <Library/BaseLib.h>
+
+/** Get bits from a value.
+
+  Shift the input value from 'shift' bits and apply 'mask'.
+
+  @param   value    The value to get the bits from.
+  @param   shift    Index of the bits to read.
+  @param   mask     Mask to apply to the value once shifted.
+
+  @return  The desired bitfield from the value.
+**/
+#define GET_BITFIELD(value, shift, mask)    \
+  ((value >> shift) & mask)
+
+UINT32  OPENSSL_armcap_P = 0;
+
+void
+OPENSSL_cpuid_setup (
+  void
+  )
+{
+  UINT64  Isar0;
+
+  OPENSSL_armcap_P = 0;
+  Isar0            = ArmReadIdAA64Isar0Reg ();
+
+  /* Access to EL0 registers is possible from higher ELx. */
+  OPENSSL_armcap_P |= ARMV8_CPUID;
+  /* Access to Physical timer is possible. */
+  OPENSSL_armcap_P |= ARMV7_TICK;
+
+  /* Neon support is not guaranteed, but it is assumed to be present.
+     Arm ARM for Armv8, sA1.5 Advanced SIMD and floating-point support
+  */
+  OPENSSL_armcap_P |= ARMV7_NEON;
+
+  if (GET_BITFIELD (
+        Isar0,
+        ARM_ID_AA64ISAR0_EL1_AES_SHIFT,
+        ARM_ID_AA64ISAR0_EL1_AES_MASK
+        ) != 0)
+  {
+    OPENSSL_armcap_P |= ARMV8_AES;
+  }
+
+  if (GET_BITFIELD (
+        Isar0,
+        ARM_ID_AA64ISAR0_EL1_SHA1_SHIFT,
+        ARM_ID_AA64ISAR0_EL1_SHA1_MASK
+        ) != 0)
+  {
+    OPENSSL_armcap_P |= ARMV8_SHA1;
+  }
+
+  if (GET_BITFIELD (
+        Isar0,
+        ARM_ID_AA64ISAR0_EL1_SHA2_SHIFT,
+        ARM_ID_AA64ISAR0_EL1_SHA2_MASK
+        ) != 0)
+  {
+    OPENSSL_armcap_P |= ARMV8_SHA256;
+  }
+
+  if (GET_BITFIELD (
+        Isar0,
+        ARM_ID_AA64ISAR0_EL1_AES_SHIFT,
+        ARM_ID_AA64ISAR0_EL1_AES_MASK
+        ) >= ARM_ID_AA64ISAR0_EL1_AES_FEAT_PMULL_MASK)
+  {
+    OPENSSL_armcap_P |= ARMV8_PMULL;
+  }
+
+  if (GET_BITFIELD (
+        Isar0,
+        ARM_ID_AA64ISAR0_EL1_SHA2_SHIFT,
+        ARM_ID_AA64ISAR0_EL1_SHA2_MASK
+        ) >= ARM_ID_AA64ISAR0_EL1_SHA2_FEAT_SHA512_MASK)
+  {
+    OPENSSL_armcap_P |= ARMV8_SHA512;
+  }
+}
+
+/** Read system counter value.
+
+  Used to get some non-trusted entropy.
+
+  @return Lower bits of the physical counter.
+**/
+uint32_t
+OPENSSL_rdtsc (
+  void
+  )
+{
+  return (UINT32)ArmReadCntPctReg ();
+}